In hexagram 3 line 3 is the character ji, which is intriguing. It can be translated as "seed", the very first beginning of something, when it is not yet really visible.
Ji means how many; a few, first sign, nearly, incipience, the seed of something.
It is composed of 幺 (small, doubled) and 戍 (frontier guard). From Wieger: Frontier guards “are attentive to the least movement, to the smallest event".
幺 is actually a picture of silk threads - very slight, thin, hardly visible.
There are more lines with this character, but all of them about the moon being 'almost' full. On the verge of being full, but just not yet. It is a moment when things can change. A full moon is a time of 'much', but being on the verge of full is a meaningful but still rather undefined moment. See 9 line 6, 54 line 5 and 61 line 6.
There is another character with the meaning 'full', which simply tells us that the moon is 'round'. But the character 'full' in these three lines also means 'hope' or prestige and it is also the name of an ancient sacrifice to the dead whose remains are buried far away, and to mountains and rivers, sun, moon and stars.